1. Field of the Invention
The present invention relates to an electronic typewriter, and more particularly it relates to an electronic typewriter in which operations for tabulation and decimal tabulation or the like can be easily carried out.
2. Description of the Prior Art
Electronic typewriters having a tabulation function (for moving a carriage to a definite position with a single key manipulation) to simplify table formation, or the like are known in the art. Among those, a large number are of the type that in addition to such ordinary tabulation function, an additional decimal tabulation function is provided. Thus, a decimal tabulation operation may also be carried out as well as a tabulation operation. In order to perform tabulation or decimal tabulation operations, the operator depresses a tab or tabulation key described later to drive and move a carriage to the next tab position or decimal position. If the stopped position is a decimal tab position, a decimal tab key input is required for further operations. As the tab key is again depressed during the decimal tabulation input, decimal tabulation printing is executed and the carriage is moved to the subsequent tab position or decimal tab position. In this case, if the stopped position of the carriage is a decimal tab position, a decimal tab key input is further required as above.
In the tabulation and decimal tabulation operations, the carriage moves in accordance with the manipulations of the tab key which the operator depresses. In the case that the stopped position of the carriage is a decimal tab position, a decimal tabulation operation is effected automatically.
With conventional electronic typewriters of this type, however, the carriage stops always at a decimal tab position even when the operator wishes to perform only a tabulation operation. Therefore, in order to move the carriage to the next tab position, the operator has heretofore been required to depress the tab key one or more additional times. Such operation will be described in connection with FIGS. 1(A) and 1(B) showing a relation between carriage positions and printed outputs. In FIG. 1(A), reference labels LM and RM designate left and right margins, respectively, reference labels T1 to T3 designate tab positions, and reference labels DT1 to DT2 designate decimal tab positions. The operations required of the operator intending to print out a series of characters "JAPAN 123.456 321.654" shown in FIG. 1(A), are as shown in FIG. 2(A). In particular, as shown in FIG. 2(A), first the tab key is depressed (step S11); a word "JAPAN" is key-input (step S12); the tab key is depressed (step S13); the number "123.456" is key-input (step S14); the tab key is depressed (step S15); the tab key is again depressed (step S16); a numeral "321.654" is key-input (step S17); and last the tab key is depressed (step S18).
Next, the operations required of the operator intending to print out a series of characters "TOTALA TOTALB" shown in FIG. 1(B), are as shown in FIG. 2(B1). In particular, as shown in FIG. 2(B1), first the tab key is depressed (step S21); a word "TOTALA" is key-input (step S22); the tab key is depressed (step S23); the tab key is again depressed (step S24); a word "TOTALB" is key-input (stepS25); and last the tab key is depressed (step S26).
Therefore, in printing out a series of characters shown in FIG. 1(B), the tab key must be depressed (as in step S23) even in the case that the decimal tabulation operation is not required. Consequently, the operator must carry out his manipulations bearing in mind a line format of both tab and decimal tab positions.